The eGo-C battery is a static 3.7V, and using a 1.2 ohm coil means you're unit was pulling near 11.5 Watts (and 3.1A) to fire that coil... I don't know the specs/limits of that battery, but I'm guessing 11.5W / 3.1A is well beyond the safety-zone. Actually, my MVP 2.0 VV/VW battery has a cut-off limitation of 11.0W, so to fire a 1.2 Ohm coil on that MOD, I'd be forced to use lower voltage... even if I set the voltage to 5.0V on a 1.2 Ohm coil, the battery would auto-limit Voltage to 3.63V and cap at 11.0W to prevent damage to the battery (and me)!
A 1.5 Ohm coil @ 3.7V is pulling 9.1W and 2.5A (within the capability of the battery)... and the lowest resistance coil I would risk on an eGo battery.... Just my opinion
You're very lucky the eGo-C has over/under protection circuitry... which is why it no longer functions... otherwise, that 1.2 Ohm coil could have caused the battery to pop in your hand, inches from your face!
I agree with everyone else... with factory coils running under a buck each, and if you're going to use a static-output eGo battery... stick with factory coils until you have the equipment and know-how to safely build and TEST your own coils.
Be safe! Get a good "coil meter", know your battery's limitations, and make use of an Ohm's Law Chart!
